Nasal dryness could herald Covid-19 infection arrival: Study

A new study on the coronavirus symptoms explored in detail the nasal symptoms that are associated with anosmia (smell blindness) and ageusia (loss of taste), including the early warning signs of infection.

These findings, published in the journal medRxiv, could help in the early diagnosis of the disease in order to practice effective quarantine measures.

According to the study, alterations in taste or smell are thought to be present in about 80 per cent of Covid-19 cases in Europe. This development is possibly linked to viral entry into angiotensin-converting enzyme 2 (ACE2)-bearing epithelial cells.

Goblet cells

Goblet cells, which are found scattered among epithelia in the respiratory and intestinal tract, are viral targets since they express ACE2. These mucin-producing cells are also in the respiratory epithelium of the nose.

The breakdown of the mucin barrier by the action of the virus on the goblet cells could also contribute to the anosmia/hyposmia, since the odorant molecules may probably stick to their receptors with the help of the mucus, the researchers wrote.

Mucus reduction could also cause strange sensations in the nasal cavity, in which case virus-induced this could also herald Covid-19 earlier than other symptoms.

For the study, the researchers examined nasal symptoms in a group of 35 patients, including only those which could possibly cause marked disruptions in olfactory function.

Researchers found that almost 70 per cent of the patient group said they had one or more nasal symptoms, including “a strange sensation in the nose,” almost 37 times more often than the control group. Over 60 per cent said they felt an abnormal dryness of the nose versus around 15 per cent of controls.

Additionally, over half of the patient group said they felt as if a strong nasal wash had been administered, while only one member of the control group reported this sensation, making the patient group risk 32-fold higher for this symptom.

In the patient group, the nasal symptoms mostly occurred in the same period as the alteration in smell and taste, or before the latter began. The mean period of such symptoms was 12 days, on average, versus 5 days in controls. Overall, about 85 per cent and 80 per cent of the patients had issues with loss of smell and taste, respectively, which is congruent with other reports on the subject.

The researchers concluded: “The presence of these nasal sensations could be taken into account for both diagnostic and social distancing purposes, especially in those situations in which RT-PCR tests cannot be administered to non-severe cases.”